Field of the Invention
Embodiments of the present disclosure generally relate to a resonator circuit for a modulated power supply of an input device.
Description of the Related Art
Input devices including proximity sensor devices (also commonly called touchpads or touch sensor devices) are widely used in a variety of electronic systems. A proximity sensor device typically includes a sensing region, often demarked by a surface, in which the proximity sensor device determines the presence, location, and/or motion of one or more input objects. Proximity sensor devices may be used to provide interfaces for the electronic system. For example, proximity sensor devices are often used as input devices for larger computing systems, such as touchpads integrated in, or peripheral to, notebook or desktop computers. Proximity sensor devices are also often used in smaller computing systems, such as touch screens integrated in cellular phones or tablet computers.
Many proximity sensor devices utilize an array of sensor electrodes to measure changes in capacitance indicative of the presence of an input object, such as a finger or stylus, proximate the sensor electrodes. For example, in “matrix sensing” implementations, sensor electrodes arranged in a grid are operated to acquire a capacitive image of an input sensing region. In some matrix sensing implementations, the grid of sensor electrodes are driven for absolute capacitance sensing, where each sensor electrodes may be driven with a signal to determine a degree of capacitive coupling between the sensor electrode and an input object.
However, sensor electrodes driven for absolute capacitance sensing may form parasitic capacitances with other components included in (or near) an input device. For example, conductive objects included in an input device proximate to the sensor electrodes may affect capacitance measurements acquired by the sensor electrodes, reducing the ability to detect the presence of an input object. Such issues are particularly problematic in common electrode implementations—where sensor electrodes are used to perform both input sensing and display updating—since the sensor electrodes are often positioned close to other conductive elements, such as pixel electrodes included in a display device.
Accordingly, there is a need for improving the operation of various types of proximity sensor devices.